Seymour Duncans come with an exchange policy if you dont like them. Personally I would stick with the original pups and drop in a J-retro preamp, it'll make a bigger difference than any pup change. I know you want to stay passive, but that's my opinion.

but what about Fender's Noiseless Jazz pickups? I've got them in my stock MIA Deluxe and I plan to add a set to my CIJ fretless. I would put them up against any of the ones that have been named but to each his/her own.